Motion sensors are today typically mounted on devices such as a cellular phone, a smart phone, a personal digital assistant (PDA), and a mobile game-playing device. The motion sensor detects a motion of a device imparted by a user of the device. The motion sensors include an acceleration sensor, a gyroscope, and a geomagnetic sensor.
Operating a motion user interface (UI) is easier than operating a mouse, a keyboard, a touch panel, or a pen. According to Japanese Laid-open Patent Publication No. 11-120360, the motion UI draws attention as a UI for operating a device simply.
Several methods and apparatuses have been proposed to identify motion. For example, an input information processing apparatus proposed includes a signal separator that separates a signal measured by an acceleration sensor mounted on a user into an acceleration signal and a muscle sound signal, and a controller controlling an operation of a user operation target in response to the acceleration signal and the muscle sound signal (as described Japanese Laid-open Patent Publication No. 2008-192004).
According to the following proposed method, a mobile terminal main body is moved in accordance with a specific operation pattern, and an acceleration of the motion of the mobile terminal main body is detected when the mobile terminal main body is moved in accordance with the specific operation pattern. In a preliminary phase to the identification of the operation pattern of the mobile terminal responsive to the detected acceleration, it is verified whether a still state in which the acceleration of the mobile terminal is equal to or below a set threshold value has continued for a specific period of time. If the still state has continued for the specific period of time, the operation is identified (as described in Japanese Laid-open Patent Publication No. 2006-139537).